Archive for the ‘Astrobiology’ Category

Why extremophiles bode well for life beyond Earth

October 9, 2013

Life on Earth requires three things: liquid water, a source of energy within a habitable range from the sun and organic carbon-based material. But life is surprisingly resilient, and organisms called extremophiles can be found in hostile living conditions (think extreme temperatures and little access to oxygen). Extremophiles give astrobiologists hope for life in the universe.

Three habitable worlds found around the same star

July 17, 2013

Astronomers believe they have found an alien solar system packed with a record-breaking three potentially habitable worlds.

New observations of the star Gliese 667C—about one-third the mass of our sun—is home to between five and seven planets, three of which are classified as super-Earths. All three are larger than our own planet, but smaller than gas giants like Uranus and Neptune.

Gliese 667 C Planet

But what makes all the difference is that these super-Earths orbit in what is known as the “Goldilocks Zone”—the region around a star where temperatures are just right for liquid water, a key ingredient in the recipe for life, to exist.

These planets are good candidates to have a solid surface and maybe an atmosphere like the Earth’s.

What makes this finding so exciting is that for the first time, astronomers have three potentially rocky or ocean worlds orbiting the same star. And at 22 light-years away from Earth, Gliese 667C and it’s two companion stars are considered relatively close neighbors to our solar system, making them ideal candidates for future extraterrestrial searches for life.

Learn more here or here.

The search for other Earth-like planets

April 27, 2013

Billions of stars. Billions of galaxies. A thousand years just to count all of the stars in our galaxy and then another thousand to count the galaxies in the universe.

The Odds of Intelligent Alien Life

January 21, 2013

Could there be intelligent life on other planets? This question has piqued imagination and curiosity for decades. Explore the answer with the Drake Equation — a mathematical formula that calculates the possibility of undiscovered life.

2012: A Banner Year in the Hunt for Exoplanets

January 5, 2013

The search for worlds outside our solar system has come a long way since the first exoplanets were confirmed in the early 1990s. Since then, the average rate of alien-world discoveries has shot from about three per year to between fifty and a hundred per year in the last five years. As of the end of 2012, with the tally standing at 854 newfound worlds and reports of new detections being announced nearly every week, thanks in large measure to NASA’s Kepler space telescope, astronomers are calling this the golden age of exoplanet discovery.

small-exoplanet

Now the race is on to find Earth’s twin, the elusive Earth-size planet in the habitable, or “Goldilocks,” zone around a star where liquid water can exist—and experts believe we may hit the cosmic jackpot soon.

In 2012 astronomers came closer than ever to zeroing in on an earthly doppelganger, or at the very least a planet considered potentially habitable.

However, we are far from confirming the habitability of any of these planets until we have the capability to observe their atmosphere, but that will take many years. The big goal now is to find an Earth-size planet in its star’s habitable zone—something more similar to Earth.

To learn about five of the most interesting exoplanetary discoveries of this past year like Gliese 667CcAlpha Centauri Bb and Tau Ceti e and f – go here.

Sugar Found In Space: A Sign of Life?

November 29, 2012

Astronomers have made a sweet discovery: simple sugar molecules floating in the gas around a star some 400 light-years away, suggesting the possibility of life on other planets.

The discovery doesn’t prove that life has developed elsewhere in the universe—but it implies that there is no reason it could not. It shows that the carbon-rich molecules that are the building blocks of life can be present even before planets have begun forming.

Scientists use the term “sugar” to loosely refer to organic molecules known as carbohydrates, which are made up of carbon, hydrogen, and oxygen.

The molecules that the team detected in space are the simplest form of sugar, called glycoaldehyde. Learn more here.

A needle in countless haystacks: Finding habitable worlds

November 11, 2012

Out of billions of galaxies and billions of stars, how do we find Earth-like habitable worlds? What is essential to support life as we know it?

Planet Found in Nearest Star System to Earth

November 5, 2012

Meeting the neighbours is normally easier than this. After years of searching, astronomers have finally spotted an Earth-mass planet in Alpha Centauri, the nearest star system to our own. Although the planet orbits too close to its parent star to host life, its discovery ups the chance of the system also hosting hospitable worlds.

Alpha Centauri looks like a single point of light from Earth, but it contains two bright stars that share a relatively close binary orbit, including one that looks a lot like our sun. This binary pair is in our cosmic backyard, about 4.3 light years away, spurring great interest in its ability to host planets.

If you’re hoping to visit the neighbours, though, you may want to pack a few books for the trip. Even with the current record holders for the world’s fastest spacecraft, the Helios sun probes, the journey to Alpha Centauri would take 19,000 years – and that’s assuming you travel at top speed for the whole journey, which is unlikely. Learn more here, here, here or here.

Researchers discover ‘waterworld’

April 9, 2012

An astronaut attempting to visit recently discovered planet GJ1214b would land in hot water – literally.

Researchers said they have identified an entirely new kind of planet, dominated not by rock, gas or other common materials, but water. The planet is “a waterworld enshrouded by a thick, steamy atmosphere.

GJ1214b was discovered in 2009 by the ground-based MEarth Project. Described as a “super-Earth,” it is about 2.7 times Earth’s diameter and weighs almost 7 times as much.

Further studies in 2010 led to scientists suspecting that the planet, where the temperature is some 232 degrees Celsius, was largely covered in water. This was confirmed by using Hubble to study the planet when it crossed in front of its host star.

The light of the star, filtered through the planet’s atmosphere, gave clues to the mix of gasses, backing up the water vapor theory. Learn more here or here.

Two Earth-Size Planets Found Around Sunlike Star

December 23, 2011

Astronomers using NASA’s Kepler mission have detected two Earth-sized planets orbiting a distant star. This discovery marks a milestone in the hunt for alien worlds, since it brings scientists one step closer to their ultimate goal of finding a twin Earth.

The two planets, dubbed Kepler-20e and 20f, are the smallest planets found to date. They have diameters of 6,900 miles and 8,200 miles – equivalent to 0.87 times Earth (slightly smaller than Venus) and 1.03 times Earth. These worlds are expected to have rocky compositions, so their masses should be less than 1.7 and 3 times Earth’s.

Both worlds circle Kepler-20: a G-type star slightly cooler than the Sun and located 950 light-years from Earth. Kepler-20e orbits every 6.1 days at a distance of 4.7 million miles. Kepler-20f orbits every 19.6 days at a distance of 10.3 million miles. Due to their tight orbits, they are heated to temperatures of 1,400 degrees Fahrenheit (760 °C)and 800 degrees F (430 °C).

In addition to the two Earth-sized worlds, the Kepler-20 system contains three larger planets. All five have orbits closer than Mercury in our solar system. They also show an unexpected arrangement. In our solar system small, rocky worlds orbit close to the Sun and large, gas giant worlds orbit farther out. In contrast, the planets of Kepler-20 are organized in alternating size: big, little, big, little, big. Learn more here, here, here, here or here.


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